The conventional screwdriver generally comprises a handle and a shaft which is integrally connected with the handle, and bits are connected to the shaft to tighten or loosen objects such as bolts and screws. There are different tips for the bits, such as the cabinet tip, the keystone tip, hexagonal tip, and the Phillips head tip, to be cooperated with different objects. In other words, users have to carry as many bits as possible to meet the practical needs. Besides, when tightening or loosening the objects, the users hold the handle to rotate the screwdriver, and then the holding hand is released to adjust the position. After adjusting, the users hold the handle again to rotate the screwdriver. The steps must be taken repeatedly to tighten or loosen the objects. This is a time-consuming task and has low efficiency. When releasing the hand from the handle, the users have to keep the screwdriver at the proper position, or the bit will be disengaged from the object. The ratchet screwdrivers improve the shortcomings and the users simply rotate the ratchet screwdrivers back and forth to tighten or loosen the objects. However, changing operating direction of the ratchet screwdriver may not be reliable because the ratchet device may be stocked or disengaged from the ratchet wheel.
The present invention intends to provide a ratchet screwdriver able to change turning direction by a switch at the rear end of the handle and improves the shortcomings of the conventional ratchet screwdrivers.